Packer's classic 1973 essay 'What did the cross achieve?' is a terrific corrective to what he calls 'rationalistic' versions of atonement theology of both conservative and non-conservative types. Some of the most interesting stuff comes at the beginning of the essay when he puts out some methodological insights...
Thus:
Here as elsewhere methodological rationalism became in the seventeenth century a worm in the Reformed bud, leading in the next two centuries to a large-scale withering of its theological flower. p. 5
Packer asks 'what sort of knowledge of God's actuon in Christ's death may we have?' (p. 6)
The answer.. is faith-knowledge: by faith we know that God was in Christ reconciling the world to himself. Yes, indeed, but what sort of knowledge is faith-knowledge? It is a kind of knowledge of which God is both giver and content. It is a Spirit-given acquaintance with divine realities, given through acquaintance with God's word. ....it is a unique kind of knowledge which, though real, is not full; it is knowledge of what is discernible within a circle of light against the background of a larger darkness; it is, in short, knowledge of a mystery, the mystery of the living God at work.
